Police officials announced Thursday that the Acre gas explosion that killed five and injured another 11 people last month was a deliberate act of sabotage.

The revelation comes at the end of a three-week investigation into the incident, during which evidence reinforced early suspicions that there was criminal intent behind the blast in the northern coastal town.

Police earlier told Army Radio they believed the suspect or suspects may have opened a gas canister in the building and placed incendiary material next to it, causing the explosion.

In addition, the police declared that two of the four suspects arrested were among those injured in the gas explosion.

Although the identity of the suspects was not released, police officials did state that they are all residents of the city, Israel Radio reported.

The police also sought an extension of the suspects’ detentions, as the investigation was ongoing.

Neighbors and relatives of victims have claimed the blast was criminally motivated, saying it was carried out as part of an ongoing quarrel.

Local residents reported a longstanding dispute between the building’s landlord and tenants over the placement of cellular antennas on its top floor. Attempts had reportedly been made to sabotage them in the past. Residents feared antennae were the source of a string of health issues. Elsewhere in Israel violent protests have been held in the past to oppose their placement.

The brother of one of the victims was threatened after publicly claiming that the explosion was a criminal act. Police Commander Eli Asayag told Maariv that Khaled Bader received numerous threats telling him to leave the old city of Acre within three days because he “informed” to police.

The explosion that caused the collapse occurred around 2 a.m. on Monday, February 17. The victims were Muhammad and Hanan Bader, and Ra’ek and Najah Sarhan and their son Hamed.

Lazar Berman contributed to this report.